Nepal lies between latitudes 26° and 31°N, and longitudes 80° and 89°E. Comprised of three ecological regions namely Himalayan, Hilly and Terai region, these regions run east to west about 800 km along its Himalayan axis, 150 to 250 km north to south, and are vertically intersected by the river systems. Mt. Everest is the highest point in the Himalayan region, whereas the lowest point is in the Terai plains of Kechana Kalan, Jhapa.

The Terai has a subtropical to tropical climate. Generally, it is lowland comprised of some hills. The plains were formed and are fed by three major Himalayan rivers: the Koshi, the Narayani, and the Karnali as well as smaller rivers rising below the permanent snowline. Rich in vegetation, the region is also known as ‘Bread basket of Nepal’. It is rich in vegetation and has hot evergreen forest. The outermost range of the foothills known as Siwalik Hills or Churia Range cresting at 700 – 1000 meters marks the limit of the galactic plain.

Hilly or Pahad region usually does not contain snow. The region lies between Himalayan and Terai regions. The mountains vary from 800 to 4,000 meters (2,600 to 13,100 ft) in altitude with progression from subtropical climates below 1,200 meters (3,900 ft) to alpine climates above 3,600 meters (11,800 ft). Rich in biodiversity various species of flora and fauna are found here. The altitude and topography makes this region rich on biodiversity.

Himalayan region situates in the Great Himalayan Range. This region with snow is comprised of with some of the highest elevations in the world including Mt. Everest (8848 m). Seven of the other eight-thousand meters above peaks are located here namely Lhotse, Makalu, Cho Oyu, Kanchenjunga, Dhaulagiri, Annapurna and Manaslu.